After coming out of the laboratory, Lu Zhou told Academician Xue to wait for a second. He then looked at the two security guards standing in the hallway and spoke in a serious tone.

“Change the security level here to Grade A. Other than me, no one is allowed near here.”

The two security guards stood at attention and performed a military salute.

“Okay.”

After they left the Institute of Semiconductors, Academician Xue walked next to Lu Zhou and asked him, “They’re from the military?”

Lu Zhou: “They’re retired from the military. I have a good relationship with the commander, who arranged them to work for me.”

He wouldn’t have to worry about any background checks. Regiment Commander Dai would only recommend the best soldiers to him. Also, any soldiers from the army that passed basic training were often much more capable than ordinary security guards.

There had never been a theft at the Jinling Institute for Advanced Study, not even a single piece of draft paper was stolen before. This was all thanks to the lovely soldiers.

After they arrived at Lu Zhou’s office, Lu Zhou told his assistant to pour a cup of tea. He then made himself a cup of coffee.

After pouring the cup of tea, the assistant left the office and closed the door.

As Lu Zhou looked at the old man sitting across from him, he smiled and said, “I’m sure you have a lot of questions, go ahead.”

After a moment of silence, Academician Xue sighed and spoke.

“Before coming here, I did have a lot of questions, but now… I feel I have the answers. Besides…”

The academician had a complicated smile on his face.

“… Cryptography is about to retire from the field of the sciences.”

Lu Zhou shook his head.

“That’s too absolute. It takes time to implement any technology. Even though we have clean and efficient fusion energy, coal energy still occupies a portion of the market…

“Besides, encryption algorithms are only going to be retired from long-distance communication. When it comes to short-distance communication and application to other fields, cryptography can still play a significant role…”

Lu Zhou looked at Academician Xue and continued, “All we have to do is make some adjustments.”

Academician Xue listened to Lu Zhou’s words and began to contemplate.

Lu Zhou picked up his hot cup of coffee and slowly took a sip,

After a few minutes passed by, Academician Xue looked up and spoke in a serious way.

“Is there anything I can do?”

Lu Zhou had an approving smile on his face.

“Of course.

“I have a few questions I need to consult with experts.”

Academician Xue: “In which field?”

“It’s about quantum communication.”

Academician Xue was slightly taken aback, and he said awkwardly, “Quantum communication… I’m not an expert in this field. You should consult a professor from the University of Science and Technology…”

“Before you came here, I already sent an email to the professors of the University of Science and Technology of China. They recommended you to me.”

Lu Zhou looked at Academician Xue and said, “In addition to cryptography, you’re also an expert in communications engineering. You were a senior engineer at the No.46 Electronics Research Institute, and you participated in the early construction of domestic optical fiber networks.”

Academician Xue felt nostalgic when he heard these things.

But, in the end, he still shook his head.

“That was the past. I’ve been in the field of communication security for the past decade. I’m afraid I won’t be of help to you.”

“I believe experience is something you keep forever.” Lu Zhou said in a serious tone, “Especially since we need to rebuild a communication network.”

When Academician Xue heard this, he looked at Lu Zhou in disbelief.

“You’re saying, you plan to… rebuild the Chinese communication network? What kind of quantum optical fiber are you going to use?”

“Not quite.”

Lu Zhou smiled and said in a joking tone, “I didn’t say the network is only going to be domestic.”

…

After the quantum repeater problem was solved, there was a real chance of commercializing quantum communication technology.

However, quantum communication technology had a fatal disadvantage, which was the speed of data transmission.

Using the submarine optical cable from the west coast of the United States to the east coast of China as an example, this cable bandwidth was measured in Terabits per second.

Data transfer speeds at this magnitude was not a difficult task for traditional optical fibers, but when it came to quantum communication technology, which relied on single-photon entanglement pairs for information transmission, this was a problem that couldn’t be solved in the short term.

Simply put, a communication channel using quantum communication technology could meet the data transfer requirements of a few companies, but it was nowhere near the scale of the internet.

However, there was a solution to this problem.

According to the IST FP5 report, a 128-bit key could secure 100 Gbit data. In theory, a quantum communication channel with a bandwidth in the magnitude of megabits per second was enough to secure all information traveling across the Pacific Ocean.

Therefore, a perfect solution might be to combine traditional communication methods with quantum communication technology. One could use traditional channels to send “encrypted information” and then use quantum channels to send “encryption keys”.

It would be like delivering a safe in one hand while delivering a key in the other.

This kind of encryption method was similar to “one-Time-Pads”. Theoretically, it was “unbreakable”. If there was only one unique key in this entire universe, it was impossible to steal the key using pure computing power.

In order to separate the transmission of the key and the encrypted information, they would need a new set of communication protocols. Moreover, in order to improve the efficiency of information transmission, the quantum communication network used to transmit keys had to be designed elegantly and carefully.

This was not an easy task.

However, it was much easier than designing a quantum repeater.

Academician Xue accepted Lu Zhou’s invitation for participating in the quantum communication network project without any hesitation. He would stay in Jinling in the name of academic exchange.

He also wanted to avoid his colleagues at the Ministry of Industry and Information Technology.

Even though it was easy to keep a secret, this industry circle was too small and tight.

Even if he didn’t say anything, people would be able to tell something was going on just by looking at his face.

Whether it was for the sake of the project or himself, staying in Jinling was the best choice.

After Academician Xue joined the project, the quantum communication network project began to quickly advance. With the old man’s help, Lu Zhou soon found an optimal method for combining quantum communication with traditional communication technology. They were able to complete a structural framework for this new communication protocol.

The days quickly went by. Soon, it was the last day of April.

An experimental quantum communication pipe with a length of around 500 meters was built at the Jinling Institute for Advanced Study. There was also a special guest visiting…